(a) Field of the Invention
The present invention relates to a plasma display panel (PDP), and more particularly, to an electrode structure of a PDP.
(b) Description of the Related Art
A PDP is a display device in which vacuum ultraviolet rays generated by the discharge of gas in discharge cells excite phosphors to realize predetermined images. As a result of the high resolution possible with PDPs (even with large screen sizes), this flat panel display configuration is quickly emerging as one of the most popular displays.
Depending on how the PDP is driven, this display configuration is classified into the different types of the AC PDP, DC PDP, and combinational PDP. The AC PDP, utilizing a triode surface discharge structure, is increasingly becoming the standard configuration. In this AC PDP, an address electrode, barrier ribs, and a phosphor layer are formed on a rear substrate corresponding to each discharge cell. Also, discharge sustain electrodes realized through scanning electrodes and display electrodes are formed on a front substrate. Discharge gas (typically an Ne—Xe compound gas) is filled in the discharge cells defined by the barrier ribs.
An address voltage is applied between the address electrodes and scanning electrodes to select a discharge cell for illumination, and if a sustain voltage of 150˜200V is applied between the scanning electrodes and display electrodes, the discharge gas causes plasma discharge, and vacuum ultraviolet rays are emitted by the plasma discharge. The vacuum ultraviolet rays excite phosphors so that they emit visible light and thereby enable color display.
In the PDP with this structure, the above electrodes are formed each with an end thereof extending into a terminal region, which lies outside a display region. Each of the ends of the electrodes is connected in the terminal region to a connecting element such as a flexible printed circuit (FPCs) or chip on film (COF). Drive voltages needed to effect plasma discharge are applied through such connections.
FIG. 4 is a schematic view of a front substrate of a conventional PDP. The front substrate is shown in a state where scanning electrodes 1 and display electrodes 3 are formed thereon.
Scanning electrodes 1 and display electrodes 3 are formed on front substrate 4 in a stripe pattern along a long axis direction of display region 5 (i.e., along direction X). Further, scanning electrodes 1 and display electrodes 3 are formed alternatingly along a short axis direction of display region 5 (i.e., along direction Y), that is, in a pattern alternating between one scanning electrode 1 and one display electrode 3. Since display electrodes 3 are common electrodes, it is not necessary that a connecting element (for example, an FPC) be connected to each of display electrodes 3. In the case of scanning electrodes 1, however, it is necessary that a connecting element be connected to each of the scanning electrodes 1 and to individually apply a drive signal to the same.
To realize such a connecting structure of scanning electrodes 1, one end 1a of scanning electrodes 1 is extended into terminal region 7 formed to the outside of display region 5. Scanning electrodes 1 are separated into groups with a predetermined number thereof in each group, and, within terminal region 7, ends 1a of scanning electrodes 1 in each group are positioned at a reduced distance to each other. Therefore, pitch A of scanning electrodes 1 in terminal region 7 is less than pitch B of scanning electrodes 1 in display region 5.
Pitch A of scanning electrodes 1 in terminal region 7 is reduced to prevent interference between the connecting elements when a plurality of connecting elements such as FPCs or COFs is mounted along a short side of front substrate 4, and also to provide spaces for the formation of align marks required when the connecting elements are connected to the terminals of scanning electrodes 1.
However, a drawback of such a configuration of the conventional PDP is that the processes involved in forming the electrodes are made complicated by minimizing the distance between scanning electrodes 1 in terminal region 7. The small distance between scanning electrodes 1 also increases the likelihood that there will be production defects. These problems are of particular concern in PDPs realized using fine pitch panels.